With the incoming air at 63 Deg F and say 3 kW of strip heat (not sure how much you actually have, I'm approaching the question theoretically) the rise only goes to less than 80 deg on 600 CFM. That...
Type: Posts; User: vangoghsear
With the incoming air at 63 Deg F and say 3 kW of strip heat (not sure how much you actually have, I'm approaching the question theoretically) the rise only goes to less than 80 deg on 600 CFM. That...
That open floor plan would work well with displacement ventilation. Uses less power, requires a lower delta T, is quiet, low velocity, very good for IAQ, works well in high roof buildings with open...
What you are describing is an ESCO, Energy Service Co, large corporate and institutional clients are well suited to ESCOs. For instance, when an ESCO finances solar panels at a sports arena. ...
Is the system new or old? Has it done this in the past or is it a new development?
Has there been recent changes to the usage in the building either in the rooms served by the units or...
Have you considered VRF system for the entire building? No need for additional zoning equipment. Controller options can be pretty extensive including commercial protocols or standalone controllers....
Ah. I was thinking the same thing. Many disconnects are not even fused, but bypassing them is dangerous and potentially deadly.
Find the guy and whap his head good.
If you do not have energy recovery units and use a large amount of outdoor air due to occupancy and it is not used for makeup for processes or other forms of exhaust and is merely relieved, then CO2...
If you don't mind a degree or two higher temp, you can save more by just raising the cooling temp a couple of degrees and keeping it constant. (Not above 80, DX equipment doesn't like return temps...
Thanks for your well reasoned response.
Believe it or not, I do have experience in the Houston area. I worked for a multinational corp with offices in Houston and engineered a project there a few...
Correct.
The OP sought Advice-for-a-High-Performance-New-Construction-in-Houston.
In response to that we could have said add a roof venting system designed to induce draft and pull outside air through a...
A 36,000 output btuh Unico chiller pulls 19 Amps at 208/230v/1 plus 560 watts for the pump. A 14 SEER condenser pulls about 23 amps at 208/230v/1. So far I'm not seeing the big deal?
We had a lot of system volume contributing as well. We used oversized 2" headers all through the 1st floor and had quite a length of run outs (light institutional project). I think it was about a 30...
If I remember correctly, the equipment costs are similar for equally sized VRF and mini chiller, but the mini chiller sales guy claimed lower installation costs, especially if PEX piping is used.
...
You might notice that I keep mentioning equipment diversity as a potential for cost savings with the mini chiller setup. I had a high mass building with 18" thick uninsulated walls that I designed a...
Fresh air should go through the AHU or a dehumidifier first to condition it before it hits the space. A slight positive pressure helps keep infiltration rates down. Infiltration is outside air that...
Good post here. I've used MultiAqua in commercial setting. The smallest heat pump they had when I used it was 5 tons, but they have smaller air cooled chillers (cooling only). Buffer tank is a...
Glad to hear you are considering the solar. Lots of advantages in new construction to keep the cost more reasonable. 30k for 6 kW isn't too bad.
I think you may lose too much efficiency using...
You can do better. Probably lowest first cost option though.
In tight, well insulated construction this is worth considering. Have you considered Photovoltaic Solar panels to offset utility...
To answer the OP question. Yes you can likely get a less restrictive register/grille. One with 0 or 22 deg def and the same blade count or one with larger blade spacing and lower blade count or any...
Since the unit is so close, that could be machine noise from the unit. Reducing the unit to better match the load could improve that. Making a larger opening might not, so holding off on that is...
How's the noise level when the system is running? Do you hear air noise (hiss) from the register? Everyone saying that it should be noisy at correct CFM for 4 tons are right. It would run about 35...
The man said it worked for 33 years. He didn't say it was efficient or quiet. A 10 x 30 duct can handle 1600 cfm at .062 inch per 100 ft of ESP. So if it's going 10 feet or 3x that, 30 ft, for...
Is there a forced power vent on the water heater and the furnace? Power venting increases the capacity allowed through the vent. Also the vent material makes a difference. Since it was used in...
Yup, big a$$ trap. In a blow through coil it should work.
Something like the AprilAire units may allow you to reduce or eliminate adding outside air to the unit (check with your sheetmetal engineer about local requirements). You may still want some outside...
They've gone green.
Did you fix the T&P relief? That fire extinguisher won't be much good if the water heater is flying through the roof.
With well insulated glass, it is not as critical that the windows have air on them as it used to be. Used to be in schools you pretty much had to run sill line radiation to take the chill off the...
Hopefully it just dropped straight down and didn't damage the coils on its way. Sheesh.
Another note to the OP. Any coils added will have some impact on the external static pressure the fan is handling and could result in reduced airflow rates. Being as this is a multistation unit, I...
I like the thought of using chilled water return as reheat. It removes a bit of the heat from the return so you get some recovery, but still allows for cooling. Cool idea. :whistle:
I've used...
That's a good point. I didn't notice mixed air temps in his post.
He did state that they were doing reheat through the VAV boxes, but I couldn't see the need for any at the discharge air...
You may be able to retrofit the chilled water coil with a wraparound heatpipe. It does like CraziFuzzy suggested and precools the incoming air to further drive out humidity then wraps around to the...
Look online for the local codes and the year of the codes being followed. There are often little changes that occur from year to year that can bite you should the inspector decide to hold you to the...
I can offer a few comments. How much insulation on the ducts depends on the surrounding space. Are the ducts going to be in conditioned space or unconditioned? Conditioned space you can get away...
Yup. He'll need colder chilled water to accomplish this. Right now the system is doing very little dehumidifying.
Two things could be happening here. First, raising the temperature in the...
Admit it, how many of you have made this photo your desktop?
It is a combination of the above and other factors that determines the btuh required to heat the house.
Such factors as the insulating value and square footage of exterior walls, roof and floor...
a BTU = British Thermal Unit.
A BTU is the amount of energy required to raise one pound of water 1 degree F.
Temperature Rise in a furnace is the difference between the air that enters the...
That should be good. What is your system capacity?
Wood framing is a usually low mass structure (not like stone, concrete, compacted earth, or brick) unless you're talking logs, but logs also have insulating value, so they are a bit of a different...
Exact wording of the 2009 IMC 307.2.1 is:
This puts it on local authorities to decide. Goes on to say you cannot discharge into street or so as to cause a nuisance. I've seen it required to...
In my experience, condensate disposal requirements vary from location to location. This is not a bad solution, the line is open to atmosphere and draining into a trap. Some areas don't want it...
The Airtrol fitting may be faulty or stuck, or you may have an air leak in the tank or gauge glass.
If you made a recent change to the heating system, that can effect the level in the tank, or...
Are you talking flex duct? If so, I agree because flex duct has higher static losses. I was talking unlined metal duct. I almost always design using metal duct for RA with minimal flex to the unit...
HVAC_Husker, I was using a straight deflection grille, which is good for 2465 CFM at -.03 sp. You are right for an angled deflection grille, 2 are needed. One 30x24 is good for about 1610 at -.03...
That is unfortunate.
I would suggest that you snake the pipe down into the drain a ways down, the pump may move the water faster than the drain is sized for handling (overfill the hydraulic...
If the drain lines are open, why don't you get a new plastic secondary drain pan and reconnect it to the existing pipe rather than put in a temporary pump?
VFD's can be used to balance CV units to run at reduced speeds to save energy, but no more than just properly re-sheaving the unit to the reduced speed needed.
They can also be used to soft...